This invention relates to a letter pattern recognition system for identifying characters, particularly, characters such as handwritten figures.
In the field of OCR (Optical character reader) art, a handwritten figure recognition algorithm for reading figures written in a predetermined blank space has almost been perfected. From the standpoint of the level of existing readers that have been put into practical use, recognition of figures that are handwritten normally and freely without paying attention to the style of the figures being read by an OCR is still unsatisfactory as compared to the human eye.
One of the conventional character pattern recognition systems is that shown in Japanese Patent Publication No. 41943/1978, which serves as an example. This system is adapted to resolve each character pattern into specific elements according to a detailed classification so that the character pattern may be identified by the frequency of occurrence of longitudinal lengths or horizontal lengths in the elements. This feature is disadvantageous in that the reliability of recognition is low. The other type of pattern recognition system is disclosed in Japanese Patent Publication No. 26975/1984. The other disclosed pattern recognition system is based on a taxonomic logic whereby each character pattern is classified into one of several large groups, depending upon whether or not it is shaped into a loop, a cap or a cap form, and is then further classified into one of several smaller groups. In this instance, the detailed classification relies upon application of the frequency of occurrence of longitudinal lengths or horizontal lengths of the specific elements, thus resulting in poor functionability or capacity.